Applications with little or no
rebound
Digitalization and the
rebound effect
Full rebound
2
A thought experiment
Budget: 100 CHFGoal: Drive as far as possible.
Fuel price: 1 CHF/L Scenario 0
Efficiency: 1 km/L
Distance: 100 km Fuel used: 100 L
Fuel price: 1 CHF/L Efficient cars
Efficiency: 2 km/L
Distance: 200 km Fuel used: 100 L
Fuel price: 2 CHF/L Increased fuel price
Efficiency: 2 km/L
Distance: 100 km
Fuel used: 50 L
No rebound
Application 1: Japanese
vending machines
Japanese vending machines (VM)
● 5.4 Millions machines (1990). → One machine per 23 Japanese.
● 3.7% of total electricity consumed in Japan (Coleman 1997).
● Biggest contribution from refrigerated VMs that are running 24/7.
● Energy efficiency improved by 58% within 15 years (since 1990).
Image source: https://commons.wikimedia.org/wiki/File:Vending_machine_of_soft_drink_and_ice_cream_in_Japan.jpg 4
[1][6]
Where is the rebound?
Hilty’s hypothesis:
● Old machines required a lot of consumers to be profitable.
→ Only installed in large offices.
● Efficient machines open up the marked:
Profitable to install in smaller offices.
Data for EU, but it is roughly the same in all economies.
Profitable locations so far.
Profitable locations with new efficient VMs.
[1]
Linear decrease of potential
customers per machine generates exponential increase of marketable VMs.
6
[1]
Worse than rebound...
A1
A2
A1 < A2
⇒ Improved energy efficiency resulted in increased overall energy consumption.
Backfire
[1]
But this was just
speculation...
How it looks in reality:
8
Energy consumption per machine.
#VMs in Tokyo.
Where is the expected rebound/backfire?
[4]
Expectation Reality
?
Underlying assumptions:
1. If money can be made, money will be made.
2. Increased efficiency ⇒ Reduced operational cost.
3. Growth of VM market is only limited
[1][4]
Limiting factors
Two additional factors limiting the growth of japanese VMs:
10
Space Fukushima nuclear disaster (2011)
Area south of meguro station.
(Image source: https://sagasoda.com)
Aerial view of the fukushima catastrophe/
(Image source: https://peaceandjustice.org.uk)
[1]
Application 2: Multi-site
conferences
General idea
12
General idea
General idea
14
System under study: 2-site event
● Between University of Zurich and Nagoya University.
● 531 participants (372 in Davos, 159 in Nagoya).
● Partially shared events due to time-difference.
Davos, CH Nagoya,
JPN
SHARED
JPN CH
8 AM 12 AM
3 PM 7 PM
CH time:
JPN time:
[2]
ICT infrastructure
16
TelePresence system by Cisco.
[2]
Fotos graciously provided by Vlad Coroamă
Social interactions during breaks
Attendees were generally satisfied with the cross-site interactions.
(Q&A, coffee breaks etc.)
[2]
Measuring environmental impact (EI)
● Investigate difference in CO2 emissions between 1-site and multi-site model.
● Non travel-related EI assumed to be the same in both models.
(I.E. Program booklet, flyers, hotel stay etc.)
● 96.3% of EI in 1-site conferences due to travel of attendees (Hischier and Hilty).
⇒ Focus only on rebound effects w.r.t. travel.
● Impact of additional ICT infrastructure needed for 2-site event was shown to be negligible (even under most pessimistic assumptions).
18
[2][7]
Assessing the travel emissions
● Estimates from ecoinvent database.
● Attendees specified specified the different travel stops, and used means of transportation.
0.17kg
0.11kg
0.24kg
Example:
1. Airplane: New York → Paris 2. Airplane: Paris → Zurich;
3. Train: Zurich Airport → Davos
[2]
Alternative scenarios
20
AS-IS
Nagoya-only Davos-only
● Hypothetical scenarios obtained from survey + extrapolation:
“Would you travel to Nagoya if the conference was only in Japan?”
● Hypothetical travel routes were calculated under very conservative assumptions: Only train + direct long-haul flight.
[2]
Results: travel emissions
CO2 (#Attendees) Davos Nagoya Total
Nagoya-only 154 t (79) 35 t (159) 189 t (238) Davos-only 84 t (372) 151 t (76) 235 t (448)
AS-IS 84 t (372) 35 t (159) 119 t (531)
[2]
Substitution: Davos-only ⇒ Davos-Nagoya
22
Attendees Davos-only Davos-Nagoya
Davos 372 372
Nagoya 76 159
76 + 83
● 76 who would have travelled to Davos, will still travel to Davos.
● 83 additional Japanese will attend if there is the possibility to attend in Nagoya.
→ This is the expected rebound: 2-site attracts more people than 1-site.
● Still: Overall reduction of CO2 by almost 50%: 235 t → 119 t. (last slide)
● Similar results in the other substitution (Nagoya-only → Davos-Nagoya).
[2]
Application 3: Real-time
feedback during showers
The salience
bias “The salience bias describes our
tendency to focus on items or information that are more
noteworthy while ignoring those that do not grab our attention.”
Image source: https://thedecisionlab.com/biases/salience-bias/ Quote source: https://thedecisionlab.com/biases/salience-bias/ 24
[1][4]
Salience bias example: Showering
● Immediate “reward” of sensual comfort during warm showers overshadow the negative EI of water and energy consumption.
● Idea: Make energy consumption more salient by real-time feedback.
● Many people indicate willingness change behaviour in order to protect environment. (Diekmann et al.
2009, Naderi 2011)
[3][10][11]
Environmental impact of showers
● On average: 45 L of hot water per 5 minutes of showering.
→ Requires 2.6 kWh to heat up.
● Water heating is second biggest contributing factor to residential energy usage.
● 14%-18% of average home’s energy use.
(Swiss Federal Office for the Environment 2013)
26 2.6 kWh
1.0 kWh
0.63 kWh
[3][8][9]
The device
● Activated automatically each shower.
→ Unit of measurement = 1 shower.
● Measures energy and water consumption.
● Also displays water temperature and duration of shower.
● Polar bear: ice floe melts as energy consumption increases.
[3]
Experimental conditions
● Duration of study: 2 month.
● Roughly 700 participating households.
● Only 1- and 2-person households were admitted.
28
Real-time condition
Control
Real-time + past feedback● Water temperature [°C]
● Water consumption [L]
● Energy consumption [kWh]
● Water temperature [°C] ● Water temperature [°C]
● Water consumption [L]
● Energy consumption [kWh]
● Water consumption of previous shower [L]
[1][4]
Results
[3]
Results
30
[3]
Results
22% drop of energy use.
[3]
Conclusion
32
Comparison of the applications
1: Japanese VM 2: Multi-site conferences 3: Real-time feedback
Rebound effect dramatically reduced by market
saturation.
⇒ Energy improvements translate directly to reduced energy consumption.
Rebound might not be as bad if the efficiency gain is sufficiently big.
Consumer “becomes more efficient” (i.e. uses less energy to shower).
⇒ Directly translates to energy savings.
[1][2][3]
The car example (cont.)
Budget: 100 CHFGoal: Drive as far as possible.
34
Fuel price: 1 CHF/L Scenario 0
Efficiency: 1 km/L
Distance: 100 km Fuel used: 100 L
Fuel price: 1 CHF/L Large efficiency increase
Efficiency: 4 km/L
Distance: 200 km Fuel used: 50 L
Fuel price: 1 CHF/L Becoming CO2 aware
Efficiency: 1 km/L
Distance: 50 km Fuel used: 50 L Japanese VM Multi-site conferences Real-time feedback
Fuel price: 2 CHF/L Limited Market
Efficiency: 2 km/L
Distance: 100 km Fuel used: 50 L
50 chf
Closing thoughts
The rebound dilemma (from an economic perspective)
36
High energy cost?
Big economic incentive to be more energy
efficient...
… in order to increase production. (Rebound!)
Improved energy
efficiency unlikely to cause rebound effects...
… but also no economic incentive.
YES NO
(Hilty, 2012) Why energy efficiency is not sufficient – some remarks on "Green by IT"
[1]
Energy sufficiency
“Energy sufficiency goes beyond energy efficiency: it’s about having enough but not using too much. It’s about doing things differently; about living well, within the limits.”
● Cycle to a nearby destination instead of using car.
● Reduce thermostat by 1 degree.
● Shower less.
Enforcing policy Enabling policy Implicit policy
“No cars allowed.” Provide public infrastructure.
(e.g. bikelanes) Social pressure.
[5]
Downshifting
38
shifting
Source: Paramount pictures
[5]
Higher income ⇒ Higher GHG emissions
Downshifting
[5][11]
Thank you :-)
40
References (1 / 3)
[1] Lorenz M. Hilty. Why energy efficiency is not sufficient – some remarks on "Green by IT", Proceedings of the 26th Environmental Informatics Conference (EnviroInfo), pp. 13-20, 2012
[2] Vlad C. Coroamă, Lorenz M. Hilty and Martin Birtel. Effects of Internet-based multiple-site conferences on greenhouse gas emissions, Telematics & Informatics, 29 (4), pp. 362-374, 2012
[3] Verena Tiefenbeck, Lorenz Goette, Kathrin Degen, Vojkan Tasic, Elgar Fleisch, Rafael Lalive and Thorsten Staake. Overcoming Salience Bias: How Real-Time Feedback Fosters Resource Conservation, Management Science, 64 (3), pp. 1458-1476, 2018
[4] Masahito Takahashi and Hiroshi Asano. Japanese Vending Machine and Display Cooler Energy Use Affected by Principal-Agent Problem, In: Quantifying the Effects of Market Failures in the End-Use of Energy, pp. 108–119, International Energy Agency, 2006
References (2 / 3)
[5] Steve Sorrell, Birgitta Gatersleben and Angela Druckman. Energy sufficiency and rebound effects (Concept paper), 2018
[6] Coleman, J. Japan’s vending machines not as upright as they look, The Sunday Gazette, 1997
[7] Hischier R and Hilty L. Environmental impacts of an international conference. Environmental Impact Assessment Review 22, 543–557, 2002
[8] Lapillonne B, Pollier K and Samci N. Energy efficiency trends for households in the EU. Report, ODYSSEE-MURE, ADEME, 2015
[9] Michel A, Attali S, and Bush E. Energy efficiency of white goods in Europe: Monitoring the market with sales data. Technical report, Topten International Services, Zürich, 2015
42
References (3 / 3)
[10] Diekmann A, Meyer R, Mühlemann C and Diem A. Schweizer Umweltsurvey 2007—Analysen und Ergebnisse (Swiss environmental survey—Analyses and results). Report to the Swiss Federal Statistical Office (BFS) and to the Federal Office for the Environment (BAFU). Technical report, ETH Zurich, 2009 [11] Naderi I. Green behavior: Concern for the self or others? AMA Summer Educators’ Conf. Proc., Vol. 22 (American Marketing Association, Chicago), 163–164., 2011
[12] Chitnis M, Sorrell S, Druckman A. Firth, S.K.; Jackson, T., Turning lights into flights: Estimating direct and indirect rebound effects for UK households. Energy Policy, 55, 234-250, 2013